A supercritical Rankine cycle using zeotropic mixture working fluids for the conversion of low-grade heat into power

作者：Chen Huijuan; Goswami D Yogi^*; Rahman Muhammad M; Stefanakos Elias K

来源：Energy, 2011, 36(1): 549-555.

DOI：10.1016/j.energy.2010.10.006

• Supercritical Rankine cycle
• Zeotropic mixture
• Organic Rankine cycle
• Low-grade heat

A supercritical Rankine cycle using zeotropic mixture working fluids for the conversion of low-grade heat into power is proposed and analyzed in this paper. Unlike a conventional organic Rankine cycle, a supercritical Rankine cycle does not go through the two-phase region during the heating process. By adopting zeotropic mixtures as the working fluids, the condensation process also happens non-isothermally. Both of these features create a potential for reducing the irreversibilities and improving the system efficiency. A comparative study between an organic Rankine cycle and the proposed supercritical Rankine cycle shows that the proposed cycle can achieve thermal efficiencies of 10.8-13.4% with the cycle high temperature of 393 K-473 K as compared to 9.7-10.1% for the organic Rankine cycle, which is an improvement of 10-30% over the organic Rankine cycle. When including the heating and condensation processes in the system, the system exergy efficiency is 38.6% for the proposed supercritical Rankine cycle as compared to 24.1% for the organic Rankine cycle.

• 出版日期2011-1